Dosing Apparatus with a Joint Arrangement

ABSTRACT

A dosing apparatus includes a dosing unit having a piston arrangement movable along a first axis in a cavity of a casing arrangement and a joint arrangement for removably connecting a first end portion of the piston arrangement to a movement arrangement arranged for moving the piston arrangement. The first end portion includes a seat that is suitable for receiving a clutch portion of the joint arrangement, that is connectable in and detachable from the seat along a coupling direction that is almost parallel to the first axis.

The present invention relates to a dosing apparatus, in particular a volumetric dosing apparatus of the piston-cylinder type, which is associable with automatic filling machines for dosing determined and precise quantities of liquid.

In the pharmaceutical, cosmetic and food field the use of volumetric piston pumps is known that are installed on filling machines for dosing fluid products with variable viscosity in containers, such as bottles, miniature bottles, phials and the like.

In such devices, which are also called dosing pumps or syringes, a piston moves linearly with reciprocating motion inside a dosing chamber made in a hollow tubular, so-called cylinder. The piston stroke enables a defined volume of liquid product to be sucked and subsequently dispensed, said volume being a function of the stroke and of the diameter of the dosing chamber. The product to be dosed enters and exits the dosing chamber respectively through an inlet and outlet opening. The inlet opening is connected to a supply conduit connected to a tank of the product, whereas the outlet opening is connected to a delivery conduit connected, for example, to nozzles or cannulas for dosing the product in the containers.

External shut-off valves are provided on the supply and delivery conduits alternatively to close and/or open the latter during syringe operation.

Some dosing syringes that replace external valves comprise switching means that is placed inside the dosing chamber and is commanded so as to connect the latter alternatively to the supply and delivery conduits in phase with the rectilinear movement of the piston. Such switching means may consist of a rotating valve inserted inside the dosing chamber, that is able to open and close the inlet and outlet openings.

Alternatively, dosing syringes are known in which the switching means is made on the piston, called the valve-piston for this reason. In this case, the piston, in addition to sliding axially, can rotate on its longitudinal axis by a preset angle, such as to place the dosing chamber alternatively in communication with the supply conduit and with the delivery conduit.

In dosing syringes, especially in the pharmaceutical field, the precision of the piston stroke is essential for the precision and accuracy of the dose.

Equally, precision in rotating the valve piston is necessary to ensure correct suction and delivery of the product to be dosed.

In dosing syringes provided with separate rotating valve and piston, the cylinder is open at both ends to enable the piston and the valve to be connected to distinct driving members that respective provide alternating linear movement and rotation.

In dosing syringes provided with valve piston, a top or bottom end portion, of the valve piston is connected to driving members that both rotate and move the piston linearly.

Known filling machines comprise supporting frames that support a plurality of dosing syringes and, if provided thereabove, support the respective driving members of the pistons and/or valves.

The supporting frames comprise shaped seats inside which the dosing syringes are insertible and removably lockable, typically by fixing brackets that are screwable to the frame by screws or by quick connections of the tri-clamp type.

Known supporting frames ensure precise and firm support of the dosing devices but impose laborious and complex assembly and dismantling procedures that may also require the use of two operators. Such procedures are even more complex and inconvenient if the dosing syringes are associated with filling machines operating in an aseptic or sterile environment and thus filling machines provided with containing cabins that enable the processing zone to be accessed in which packaging of the product occurs only through openings provided with gloves (“gloveports”).

When the driving members are arranged above the syringes they are housed inside suitable containing casings as they comprise motors, transmission and kinematic mechanisms, sensors, etc that for reasons of cleanliness and hygiene have to be separated from the process zone.

The dimensions and the position of the aforesaid containing casings nevertheless have some drawbacks, which include a reduction in the accessibility to the process zone and to the operating means located there, the need to access the interior of the process zone (compromising the sterility thereof if provided) if failures or breakage of the aforesaid mechanical members and components occur to permit maintenance tasks to be performed. In addition, if the sterile and/or aseptic process zone is subject to a flow of sterile air the dimensions and position of the aforesaid containing casings cause the airflow to be deviated or altered at the dosing zone and the risk that owing to the movement of the pistons of the dosing syringes particles may be generated that may be dragged by the airflow inside the containers below, contaminating the containers.

In order to overcome such drawbacks, particularly in the packaging of pharmaceutical products, the current trend is to have dosing syringes that are rotated and moved rectilinearly from the bottom so as to have corresponding movement members located inside a base of the filling machine.

For this purpose, a drive shaft exits the base of the filling machine and is removably connected to a lower end of the piston of the syringe by a joint of prismatic type that provides the necessary precision in the transmission of linear motion and rotation and at the same time enables the syringe to be assembled and dismantled.

In particular the aforesaid joint typically comprises a T-shaped element, fixed to the end of the piston and housed in a seat with a complementary shape that is obtained on an upper end of the drive shaft. The T-shaped element can slide inside the seat transversely, typically perpendicularly, to the movement direction of the piston. In this manner, the T-shaped element can be inserted and detached from the seat respectively to connect or disconnect the syringe to or from the movement members. Nevertheless, in order to enable the T-shaped element to be removed from the seat in any operating position of the piston, the stem of the latter has to be of a length that is such as to enable the lower end thereof to remain always outside the cylinder.

Owing to the considerable length of the pistons such dosing syringes are bulky and difficult to handle and above all to assemble and dismantle. Also the dimensions and the space requirements of the supporting frames that are necessary for supporting the aforesaid dosing devices are significant and such as to limit considerably accessibility to the processing zone of the filling machine.

Known dosing devices are generally made of stainless steel, a material that is suitable for contact with pharmaceutical and/or food products and which can undergo cleaning and sterilising procedures.

Further, using ceramic materials owing to which it is possible to make components that have narrow dimensional tolerances and reduced surface roughness values is known.

Ceramic materials have very high coefficients of resistance to wear and to high temperatures and extremely moderate thermal expansion coefficients. The aforesaid features make ceramic materials particularly suitable for making high-precision piston pumps that are set up for cleaning and sterilising-in-place operations.

Ceramic materials nevertheless have limits in the mechanical field, inasmuch as they are relatively fragile, easily subject to breakage, fractures and splintering.

For this reason the cylinders of pumps made of ceramic material are covered by a metal liner, typically made of stainless steel. The latter is hot-mounted through interference in such a manner as to form a single monolith body with the ceramic cylinder.

The external metal casing, in addition to protecting the ceramic internal cylinder, enables the syringe to be fixed to the supporting frame and the fittings of the supply and delivery conduits to be connected thereto.

In many applications, especially in the pharmaceutical field and in the foodstuffs field, it is required that the dosing syringes can be subjected to cleaning and sterilising operations in place, without any component thereof needing to be dismantled. Such operations, which are known by the name of CIP/SIP (Cleaning In Place/Sterilising In Place), substantially consist of a sequence of steps that are performable automatically or semiautomatically, in the course of which the inner part of dosing syringes is traversed by cleaning liquids at different temperatures and by pressurised steam. In this manner, within a relatively short space of time it is possible to clean and sterilise all the parts of the syringe that came into contact with the product.

An essential condition for the correct and valid performance of a cleaning and sterilising operation is that each internal surface of the syringe that has been in contact with the product is appropriately reached and lapped at the necessary flowing speed by the cleaning and sterilising fluids.

In addition to this, the structure and conformation of the syringe has to ensure correct draining and emptying of such fluids at the end of the cleaning and sterilising cycles, i.e. the absence of zones in which said fluids can accumulate and stagnate. In particular, the dosing syringes set up for CIP/SIP operations comprise a cleaning and sterilising chamber connected to and coaxial with the dosing chamber, and provided with an opening for the exit of the cleaning and sterilising fluids. In one syringe cleaning and sterilising configuration, the piston is positioned inside the cylinder, in such a manner that the portions thereof that come into contact with the product are spaced away from the internal walls of the dosing chamber and of the cleaning and sterilising chamber. In this manner, the aforesaid portions of the syringes and the internal walls of the entire dosing chamber can be reached by the cleaning and sterilising fluids.

FR 2797046 illustrates a volumetric dosing device comprising a hollow body defining a dosing chamber, provided with a supply conduit and with a delivery conduit of the product to be dosed, and a piston that is movable linearly and in rotation inside said dosing chamber. The latter extends below in a secondary chamber, arranged for housing an extension of the piston and closed on the bottom by a closing element, removably connected to the hollow body and provided with a conduit for discharging the cleaning and sterilising fluids. The device further comprises a cleaning and sterilising chamber placed above the dosing chamber and provided with an inlet conduit for the cleaning and sterilising fluids. The cleaning chamber consists of a cylindrical tubular element removably connected to the hollow body and provided with a gap connected to the inlet conduit and separated from the cleaning and sterilising chamber by a cylindrical baffle provided with transverse holes.

One drawback of the aforesaid dosing device is the complex bulky and costly structure thereof, this structure comprising, amongst other things, four distinct conduits for the entry and exit respectively of the product to be dosed and of the cleaning and sterilising fluids.

WO 2004027352 discloses a volumetric dosing device comprising a hollow body defining a dosing chamber, provided laterally with a supply conduit of the product to be dosed, and a piston that is movable linearly and in rotation inside said dosing chamber. The latter is closed above by a closing element, removably connected to the first hollow body and provided with a delivery conduit of the product to be dosed. A further hollow body, connected to a lower end of the hollow body, forms a cleaning and sterilising chamber provided at the bottom of a discharge conduit of the cleaning and sterilising fluids.

The aforesaid dosing syringe has a more compact and simpler structure than the syringe illustrated in FR 2797046, but is more demanding and laborious to handle as the piston may accidentally exit from the hollow bodies, during transport, thus becoming damaged and/or soiled.

Both the aforesaid dosing devices consisting of a plurality of components (hollow bodies, closing elements) that are removably connected to one another, can nevertheless have cleaning and sterilising problems. In fact, it is possible that, owing to imprecision in the machining of the components and/or non-optimum coupling between components, in the interface or connecting zones of the latter there are slits or interstices of dimensions that are such as to permit infiltration and diffusion of the product to be dosed and/or of the cleaning and sterilising fluids. In this case, in order to perform correct and complete cleaning of the syringe, it is necessary to dismantle the latter completely, thus increasing operating time and consequently increasing running costs.

Another drawback of the dosing devices disclosed above lies in the complex and delicate manual procedures that are necessary for correctly assembling the syringes and subsequently mounting the syringes on the filling machine. Such procedures require specialised and therefore costly personnel.

One object of the present invention is to improve known volumetric dosing apparatuses, in particular dosing apparatuses of the valve piston type that are associable with filling machines.

Another object is to make a dosing apparatus comprising a dosing unit arranged for being connected to or disconnected from piston driving means provided in the filling machine, automatically, without requiring the manual intervention of an operator and regardless of the operating position of the aforesaid piston.

A further object is to make a dosing apparatus comprising joint means that is able to connect or disconnect the piston quickly and automatically to and from the corresponding movement means, said joint means at the same time ensuring precise and accurate transmission of the linear motion and rotation motion to the aforesaid piston.

Still another object is to make a dosing apparatus comprising supporting and locking means, associable with the filling machine that enables the dosing unit to be assembled and dismantled easily and quickly, said supporting and locking means ensuring precise and firm positioning of the dosing unit in an mounting operating configuration.

A still further object is to obtain a dosing unit that is able to dose with great precision and accuracy quantities of liquid in desired volumes and is further set up for cleaning and sterilising-in-place (CIP/SIP) operations.

Another further object is to make a dosing unit that has a particularly simple and compact structure and is at the same time tough and resistant to blows.

Still another object is to make a dosing unit that requires minimal and simple manual procedures for assembling and/or mounting the dosing unit on supporting and locking means.

According to the invention a dosing apparatus according to claim 1 is provided.

Owing to the dosing apparatus of the invention it is possible to connect or disconnect piston means of a dosing unit to/from movement means without any need for an end portion of the aforesaid piston means having to protrude outside the dosing unit. In particular, said end portion can always be contained, in any operating position, inside a cavity of the dosing unit.

This enables the length of the piston means to be reduced and a dosing unit to be made that has compact longitudinal dimensions and is thus particularly suitable for use in filling machines that require ample accessibility to the processing zone.

The piston means is further connectable to or detachable from the, movement means, in a completely automatic manner, without requiring the manual intervention of an operator and thus with reduced downtime and less risk of error in mounting.

The invention can be better understood and implemented with reference to the enclosed drawings that illustrate an embodiment thereof by way of non-limiting example, in which:

FIG. 1 is a partially sectioned frontal view of the dosing apparatus of the invention in a mounting configuration;

FIG. 2 is a partial side view of supporting means of the apparatus in FIG. 1;

FIG. 3 is a section along line III-III di FIG. 1;

FIG. 4 is an enlarged detail of FIG. 1, showing joint means in an aligned operating configuration;

FIG. 5 is a partially sectioned and enlarged view of the joint means in the aligned operating configuration;

FIG. 6 is a partially sectioned frontal view of the joint means in a misaligned operating configuration;

FIG. 7 is a partially sectioned side view of the joint means in the misaligned operating configuration;

FIG. 8 is a partial and partially sectioned frontal view of a version of the apparatus in FIG. 1;

FIG. 9 is an enlarged detail of FIG. 8, showing joint means in an aligned operating configuration;

FIG. 10 is a partially sectioned side view of the joint means in FIG. 9, in a misaligned operating configuration;

FIG. 11 is a frontal view like that in FIG. 9, showing the joint means in the misaligned operating configuration;

FIG. 12 is a partial and enlarged view of the apparatus in FIG. 1, showing supporting means and fixing means in a mounting configuration;

FIG. 13 is a longitudinal section of a dosing unit of the apparatus in FIG. 1 in a cleaning and sterilising configuration.

With reference to FIGS. 1 to 7, there is illustrated a dosing apparatus 1 that is associable with a filling machine and comprising a dosing unit 2 that includes piston means 3, comprising a piston that is movable along a first longitudinal axis W1 in a cavity 4 of casing means 5 to draw a desired quantity of liquid from an inlet 82 of the casing means 5 and direct the quantity of liquid to an outlet 83 of the casing means 5.

The apparatus 1 comprises supporting means 40 that is, for example, fixable to an external wall 102 a of a base 102 of the filling machine and arranged for supporting and locking the dosing unit 2 in a mounting configuration A.

The apparatus 1 also comprises joint means 10 for removably connecting, in said mounting configuration A of the dosing unit 2, a first end portion 6 of the piston means 3 to movement means 101 arranged for moving said piston means 3 linearly and rotationally.

The movement means 101, which is of known type and is not illustrated in detail in the figures, is contained inside the basement 102 of the filling machine.

With reference to the embodiment illustrated in the figures, the first end portion 6 of the piston means 3 is the lower end portion, the dosing unit 2 thus being driven from the bottom by the movement means 101.

The piston means 3 is of the valve piston means and comprises a second end portion 7 that is opposite the first end portion 6, is slidable inside the cavity 4 and provided with a switching means 9 that connects the cavity 4 to the inlet 82 or to the outlet 83.

The piston means 3 driven by the movement means 101 is movable by reciprocating linear movement along the first axis W1 between a retracted or internal position and an extended or external position, and is movable around the first axis W1 with a rotating movement that is also reciprocating, between a suction position in which the switching means 9 connects the cavity 4 to the inlet 82 and a delivery position, in which it connects said cavity 4 to the outlet 83.

The casing means 5 of the dosing unit 2 comprises an internal tubular element 51, with a substantially cylindrical shape, inside which the cavity 4 is made, and an external covering element 52 that envelops the internal tubular element 51 and extends to an end, for example a lower end, of the latter in such a manner as to form a further cavity 53 provided with a respective opening 56 for the passage of the joint means 10. The internal tubular element 51 is made, for example, of ceramic material, whereas the covering element 52 is made of plastics. In particular, the covering element 52 is moulded directly, for example by injection-moulding, around the internal tubular element 51 in such a manner as to form a single body with the latter.

The covering element 51 further comprises a handle-shaped gripping portion 52 a, to enable the dosing unit 2 to be easily gripped and handled by an operator, particularly during a mounting/dismantling step as explained in detail further on in the description.

The cavity 4, which has a substantially cylindrical shape and extending longitudinally for the entire length of the internal tubular element 51, comprises a lower dosing chamber 4 a and an upper dosing chamber 4 b that have different diameters and lengths. In particular, the lower dosing chamber 4 a has a greater diameter than that of the upper dosing chamber 4 b.

The upper dosing chamber 4 b is flowingly connected via the inlet 82 to a circuit supplying the product to be dosed, said inlet 82 comprising a respective conduit made on side walls of the tubular element 51 and of the covering element 52 and being transverse, in particular almost orthogonal to said first axis W1. The upper dosing chamber 4 b is further flowingly connected to a delivery circuit of the product via the outlet 83, consisting of a respective conduit, for example made on a top portion 52 b of the covering element 52, which closes the cavity 4 above, said respective conduit being, for example, substantially coaxial with the first longitudinal axis W1.

The inlet 82 and the outlet 83 are provided externally with fittings 82 a, 83 a for quick connection to the supply and delivery circuits, for example Tri-clamp quick connections. The fittings 82 a, 83 a are made directly on the covering element 52.

The dosing unit 2 of the invention is set up for cleaning and sterilising in place CIP/SIP operations. Such operations, which do not require any component of the dosing unit 2 to be dismantled, comprise a sequence of steps that can be performed automatically or semiautomatically, in the course of which the inside of the unit is traversed by cleaning liquids at different temperatures and by pressurised steam. For this purpose, the covering element 52 extends below the tubular element 51 in such a manner that a lower cylindrical portion 52 c forms the further cavity 53 that acts as a cleaning and sterilising chamber in a CIP/SIP operating step of the dosing unit 2. The further cavity 53 has a substantially cylindrical shape and has a diameter that is greater than that of the lower dosing chamber 4 a. The further cavity 53 is flowingly connected to an external drainage circuit of the cleaning and sterilising fluids via a further outlet 54, comprising a cleaning conduit, provided with a corresponding fitting 54 a for quick connections.

The piston means 3 comprises an elongated cylindrical body that includes an intermediate portion 8 between the first end portion 6 and the second end portion 7, said portions being amongst themselves coaxial to the first longitudinal axis W1 and having different diameters and lengths.

The intermediate portion 8 is arranged for sealingly sliding inside of the lower dosing chamber 4 a, whereas the second end portion 7 is arranged for sealingly sliding in the upper dosing chamber 4 b.

The first end portion 6 slides with clearance inside the further camera 53.

In a cleaning and sterilising configuration L, the piston means 3 is arranged in such a manner as to connect the cavity 4 in a flow connection to the further cavity 53 and to the further outlet 54. In particular, in the cleaning and sterilising configuration L, the second end portion 7 and the intermediate portion 8 of the piston means 3 are contained respectively completely inside the lower dosing chamber 4 a and the further cavity 53, whereas the first end portion 6 of the piston means 3, partially contained inside the further chamber 53, shuts the opening 56 of the further cavity 53. More precisely, an external side wall 6 a of the first end portion 6 sealingly abuts on seal means 55, comprising for example an annular seal of the O-ring type and provided in a respective internal wall of the further cavity 53 in such a manner as to provide a flow connection between the latter and the external environment (FIG. 13). In this manner a cleaning and/or sterilising fluid delivered inside the cavity 4 through the inlet 82 and/or the outlet 83 can reach and lap with the necessary speed all the points of the dosing chambers 4 a, 4 b and of the piston means 3 that have come into contact with the product to be dosed.

It should be noted that owing to the structure and the embodiment of the dosing unit 2 of the invention, in the interface or coupling zones between the covering element 52 and the internal tubular element 51 the presence of slits, interstices or the like is excluded in which the product to be dosed, or the cleaning and sterilising fluids, may become deposited, making the CIP/SIP operations ineffective or at least unacceptable.

The covering element 52 that is made of plastics therefore not only coats and protects the ceramic internal tubular element 51 from shocks and blows but also enables the dosing unit 2 to be fixed to the supporting means 40 and enables the supply and delivery circuits of the product to be dosed and drainage circuits of the cleaning and/or sterilising fluids to be connected to the dosing unit 2 via the fittings 82 a, 83 a, 54 a.

The first end portion 6 of the piston means 3 comprises a seat 16 configured for removably receiving a clutch portion of the joint means 10, the clutch portion 11 being connectable in, and disconnectable from, said seat 16 along a coupling direction T substantially parallel to said first axis W1.

The clutch portion 11 and the seat 16 have a complementary shape, for example a cylindrical shape, and dimensions such as to minimise residual radial clearance.

The joint means 10 comprises a connecting element 25, that includes the clutch portion 11, and a further connecting element 26 an end portion of which is connected to the movement means 101. The connecting element 25 and the further connecting element 26 are rotatably connected by a spherical element 27.

The further connecting element 26 is moved by the movement means 101 along and around a second axis W2. In use the joint means 10 is normally assembled on the movement means 101. Locking means 12 is provided for reversibly fixing the clutch portion 11 of the first connecting element 25 in the seat 16. The locking means 12 comprises one or more stop elements 13, for example two, associated with the clutch portion 11 and movable in such a manner as to engage or disengage respective housings 39 made in the seat 16 respectively to lock or release the first end portion 6 on/from the joint means 10. Actuating means 14 acts on the stop elements 13 to push the latter inside the housings 39.

With reference to the embodiment illustrated in the figures, the stop elements 13 have a spherical shape and are inserted into openings 18, made opposite on a side wall 19 of the clutch portion 11, from which they are maintained protruding by the actuating means 14, housed in a gap 17 made inside the aforesaid clutch portion 11. The actuating means 14 comprises a pressing element 15 that is slidable inside the gap 17 and provided with a tilted wall 15 a acting on the stop elements 13.

The pressing element 15 defines with a bottom wall of the gap 17 a sealed lower chamber 21 to which a pressurised fluid, typically compressed air, is supplied. On the side opposite the lower chamber 21 there is provided an elastic element 22, for example a coil spring inserted into the aforesaid gap 17 and arranged in such a manner as to exert an elastic force that opposes the action exerted by the pressurised fluid.

The housings 39 are formed, for example, by an annular groove made on a internal wall of the seat 16 and shaped in such a manner as to receive the protruding portion of said stop elements 13.

In one coupling configuration B of the joint means 10, the stop elements 13 pushed by the pressing element 15, which is in turn pushed by the spring 22, protrude from the openings 18 and engage the housings 39 in such a manner as to firmly lock the clutch portion 11 on the first end portion 6.

In particular, an annular end face 6 b of the first end portion 6 abuts on an upper face 20 a of an annular crown 20 of the clutch portion 11.

In a release configuration, which is not shown, the pressing element 15 is moved by the pressurised fluid supplied to the lower chamber 21 to a position that is such as to enable the stop elements 13 to return inside the openings 18 such as to disengage the housings 39 and to enable the clutch portion 11 to be disengaged from the first end portion 6.

Transmission means is provided for connecting the first end portion 6 to the clutch portion 11 such that the latter can transmit rotation torque.

The transmission means comprises at least one dowel 23 fixed to the clutch portion 11 and arranged for engaging in a further seat 24 obtained on the first end portion 6.

In particular, the dowel 23 is fixed to the upper face 20 a of the annular crown 20 substantially parallel to the first axis W1 in such a manner as to be connected to or disconnected from the further seat 24 when the clutch portion 11 is respectively inserted into or detached from the seat 16.

The connecting element 25 comprises a fork portion 35 opposite the clutch portion 11, whereas the further connecting element 26 comprises a further fork portion 36 opposite the end portion fixed to the movement means 101.

The fork portion 35 and the further fork portion 36 are rotatably connected by the spherical element 27. The fork portions 35, 36 comprise respective pairs of arms that partially enclose the spherical element 27, said pairs of arms being arranged on respective planes that are substantially orthogonal to one another.

The spherical element 27 permits corresponding rotation between the two connecting elements 25, 26, simultaneously ensuring the transmission of traction/compression force between the movement means 101 and the piston means 3, to ensure the reciprocating motion of the latter along the first axis W1.

The joint means 10 further includes a sleeve 38 that surrounds and contains the fork portions 35, 36. The sleeve is connected to the connecting elements 25, 26 by respective pins 29, 30.

In particular, a first pin 29 connects the sleeve 38 on the connecting element 25, whereas a second pin 30 connects the sleeve 38 on the further connecting element 26.

The first pin 29 and the second pin 30 have a cylindrical shape and are arranged substantially parallel and transversely to one another, in particular substantially orthogonally to the first axis W1.

The first pin 29 is fixed at respective opposite ends to the sleeve 38, for example by coupling through interference, whereas it is rotatably housed in a first through opening 31 of the connecting element 25. The first through opening 31 substantially comprises a through slot, having a cross section that is shaped in such a manner as to leave the first pin 29 a radial clearance of a set amount only in a direction parallel to the first axis W1.

Similarly, the second pin 30 is fixed at respective opposite ends to the sleeve 38, for example by coupling through interference, whereas it is rotatably housed in a second through opening 32 of the further connecting element 26. The second through opening 32 has a cross section that is calibrated and substantially equivalent to that of the second pin 30 to enable the latter to rotate only around the respective longitudinal axis with almost zero radial clearance.

The sleeve 38, owing to the pins 29, 30 rotatingly connects the two connecting elements 25, 26 i.e. it is able to transmit rotation torque or twisting moment.

The joint means 10 further comprises bellows means 33 that connects the clutch portion 11 of the connecting element 25 to an external wall 102 a of the base 102 of the filling machine for enclosing and separating at least the fork portions 35, 36, the spherical element 27, the sleeve 38 and the pins 29, 30 from an external processing environment 80 in which dosing of the product occurs.

The joint means 10 thus constitutes a constant-velocity joint that is able to transmit movement torque and an axial force with great precision between the movement means 101 and the piston means 3 even if the latter are not aligned.

As illustrated in FIGS. 6 and 7, the connecting elements 25, 26 rotatably connected by the spherical element 27, and the first pin 29 that is slidable in the first through seat 31 enable the joint means 10 to operate even if the first axis W1 of the piston means 3 is misaligned and/or tilted in relation to the second axis W2 of the further connecting element 26 owing, for example, to mounting and/or manufacturing imprecisions of the dosing unit 2 and/or of the supporting means 40.

In a mounting step, after an operator has fixed the dosing unit 2 to the supporting means 40 in the mounting configuration A, the movement means 101 is activated in such a manner as to move the joint means 10, that is mounted thereupon, along the second axis W2 until the clutch portion 11 is inserted inside the seat 16 of the first end portion 6. By activating the locking means 12 in the coupling configuration B it is thus possible to lock the clutch portion 11 firmly on the first end portion 6, i.e. connect the piston means 3 to movement means 101.

By performing the opposite operation, i.e. first deactivating the locking means 12, to disengage the stop elements 13 from the housings 39 of the seat 16, and by subsequently activating the movement means 101, it is possible to disengage the clutch portion 11 from the seat 6, decoupling the piston means 3 from the joint means 10 and thus from the movement means 10.

It should be noted that by virtue of the configuration of the joint means 10 and of the piston means 3 of the dosing apparatus 1 of the invention—which enables the clutch portion 11 to be inserted into and detached from the, seat 16 of the first end portion 6 along a coupling direction T that is almost parallel to the first axis W1—it is possible to connect or disconnect the piston means 3 to/from the movement means 101 without any need for the first end portion 6 to be positioned outside of the casing means 5. In particular, the first end portion 6 is always advantageously contained, in any operating position thereof, inside the further cavity 53 of the casing means 5.

This enables the length of the piston means 3 to be reduced and a dosing unit 2 to be made that has compact longitudinal dimensions and is thus particularly suitable for use in filling machines that require ample accessibility to the processing zone.

The piston means 3 is further connectable to or detachable from the, movement means 101 via the joint means 10, in a completely automatic manner, without requiring the manual intervention of an operator and thus with reduced downtime and less risk of error in mounting.

FIGS. 8 to 11 illustrate a version of the dosing apparatus 1 that differs from the previously disclosed embodiment for joint means 110 that connects a first end portion 106 of the piston means 103 to the movement means 101.

The joint means 110 comprises a connecting element 125 with an elongated shape and provided at one end of a clutch portion 111 arranged for engaging in a seat 116 obtained in the first end portion 106. The remaining end of the connecting element 125 is on the other hand connected to the movement means 101, such as to be linearly movable along and rotate around a second longitudinal axis W2.

Also in this case, the clutch portion 111 is connectable to and detachable from said seat 116 along the coupling direction T that is substantially parallel to the first axis W1 or tilted by a few degrees in relation to said first axis W1, as explained in greater detail further on in the description.

The clutch portion 111 and the seat 116 have a complementary shape, for example a frustoconical shape.

The joint means 110 comprises locking means 112 arranged for reversibly locking the clutch portion 111 in the seat 116. The locking means 112 includes seal means 113 fixed to an end of the clutch portion 111 and abutting on a internal wall of the seat 116. The seal means 113 comprises, for example, a ring seal made of elastomeric material housed in annular cavity 132 made on the end of the clutch portion 111. The end of the clutch portion 111, the seat 116 and seal means 113 define an upper chamber 121 of the locking means 112 that is connected via a conduit 122, to a vacuum source, for example a vacuum circuit. In one coupling configuration B, owing to the negative pressure or vacuum that is created in the upper chamber 121, the clutch portion 111 firmly engages the seat 116 at a connecting force the size of which depends on the shape and dimensions of the upper chamber 121 and on the vacuum values therein.

When the upper chamber 121 is returned to atmospheric pressure, for example by interrupting the connection with the vacuum circuit, the clutch portion 111 can be easily and smoothly detached from the seat 116 to enable the piston means 103 to be detached from the movement means 101.

Abutting means is provided for defining a reciprocal axial position along the first axis W1 between the first end portion 106 of the piston 103 and the clutch portion 111 of the connecting element 125, in the coupling configuration B. The abutting means comprises a first abutting pin 114 fixed to a bottom wall 116 a of the seat 116 and a second abutting pin 115 fixed to the clutch portion 111. An intermediate element 126 that has a spherical shape and is elastically connected to the clutch portion 111 is interposed between the two abutting pins 114, 115.

In the coupling configuration B, the abutting pins 114, 115 contact the intermediate element 126 on opposite sides with a connecting force made by the upper chamber 121 placed under negative pressure. It should thus be noted that in the coupling configuration B there is zero axial clearance between the piston means 103 and the connecting element 125. The intermediate element 126 also acts as a shutter to close the connection between the upper chamber 121 or the outside environment and the conduit 122, when the clutch portion 111 is detached from the seat 106.

For this purpose, the clutch portion 111 comprises a further gap 117 on the bottom of which is fixed the second abutting pin 115 and inside which is inserted the intermediate element 126. A further elastic element 118, for example a coil spring, envelops the second abutting pin 115 and acts on the intermediate element 126 so as to push the intermediate element 126 outside the further gap 117. In a release configuration in which the clutch portion 111 is detached from the seat 106, the further spring 118 pushes the intermediate element 126 to abut on an annular ridge 119 and adjacent further seal means 139, provided on a mouth portion of the further gap 117. In this position the abutting element 126 sealingly shuts the further gap 117, connected via the conduit 122 to the vacuum source.

Transmission means is provided for connecting the first end portion 106 on the clutch portion 111 such that the latter can transmit rotation torque.

The transmission means comprises one or more dowels 123, for example two, spaced apart at an angle, for example 180°, fixed to a side wall 131 of the clutch element 111 and arranged for engaging in corresponding further seats 124 obtained on the first end portion 106.

The dimensions of the dowels 123 and of the further seats 124 are such as to minimise radial clearance between the piston means 103 and the connecting element 125, to ensure the aforesaid piston means 3 the necessary precision and accuracy in rotation motion during operation.

The dowels 123 are fixed substantially perpendicularly to a longitudinal axis of the connecting element 125 in such a manner as to inserted into or detached from the, further seats 124 when the clutch portion 111 is respectively inserted into or detached from the seat 106. The further seats 124 comprise respective slots that are open below.

The joint means 110 comprises bellows means 133 that connects the clutch portion 111 of the connecting element 125 to an external wall 102 a of the base 102 of the filling machine to close an opening for the passage of the connecting element 125, made in said external wall 102 a, by the processing environment 80.

In the coupling configuration B of the joint means 111, the seal means 113 is crushed between the clutch portion 111 and the internal wall of the seat 116 by the connecting force generated by the negative pressure in the upper chamber 121. The elasticity and deformability of the seal means 113, not only ensures the insulation of the upper chamber 121 from the external environment, but during normal operation of the dosing unit is able to transmit rotation torque or twisting moment between the connecting element 125 and the first end portion 106 of the piston means 103.

If the seal means 113 slides in relation to the internal wall of the seat 116 or in relation to the annular cavity 132 of the clutch portion 111 the transmission means, in particular the dowels 123 and the further seats 124, ensure correct angular positioning between the piston means 103 and the connecting element 125 and correct transmission of the rotation torque.

As illustrated in FIGS. 10 and 11, owing to the elasticity and deformability of the seal means 113, to the frustoconical shape of the clutch portion 111 and of the seat 106 and to radial clearance between the latter, the joint means 111 is able to transmit to the piston means 103 a linear and rotation movement in a precise and accurate manner, even if the first axis W1 and the second axis W2 are misaligned and/or tilted in relation to one other.

The joint means 110 that is made also in this constructional version constitutes a constant-velocity joint that is able to transmit with great precision rotation torque and an axial force between the movement means 101 and the piston means 103 also in the case of imprecisions in the mounting and/or the manufacture of the dosing unit 2 and/or of the supporting means 40.

Also in this version of the dosing apparatus 1 it is possible to connect and disconnect in a selective manner the piston means 3 to/from the movement means 101 automatically without the manual intervention of an operator, with the first end portion 106 always arranged inside the casing means 5 in any operating position.

With particular reference to FIGS. 1 to 3 and 12, the dosing apparatus 1 comprises coupling means 60 associated with the casing means 5 and arranged for slidably engaging in guiding means 41 of the supporting means 40 in the mounting configuration A of the dosing unit 2. The coupling means 60 is insertible into or detachable from the guiding means 41 along a first direction X, substantially parallel to the first longitudinal axis W1. The first direction X is, for example, vertical and substantially orthogonal to the upper wall 102 a of the base 102 of the filling machine to which the supporting means 40 can be fixed.

In one version of the apparatus 1 that is not shown, the first direction X may be, for example, horizontal and substantially orthogonal to the first axis W1.

The supporting means 40 includes a supporting body 46 fixed to the upper wall 102 a and supporting the guiding means 41. The latter comprises a guiding element that has a flat shape and is provided with a rectilinear groove 49 that has an f-shaped cross section and extends parallel to the first direction X.

The coupling means 60 comprises a T-shaped coupling element fixed to the casing means 5 in such a manner as to engage slidably in the rectilinear groove 49 with preset clearance to enable the dosing unit 2 to be easily mounted on and dismantled from the supporting means 40.

The coupling element 60 is, for example, obtained directly on a side wall of the lower cylindrical portion 52 c of the covering element 52.

Alternatively, the coupling element 60 can be a distinct element and be fixed to the aforesaid lateral wall of the lower cylindrical portion 52 c.

The supporting means 40 further comprises fixing means arranged for reversibly locking the coupling element 60 to the guiding means 41. The fixing means comprises at least two fixing elements 42, 43 associated with the guiding means 41 and movable in such a manner as to engage with or disengage from respective coupling notches 62, 63 of the coupling element 60 respectively to lock or release the coupling means 60 to, or from the guiding means 41.

Pushing means is provided for acting on the fixing elements 42, 43 and pushing the latter to abut on the coupling notches 62, 63 with a preset fixing force along a second direction Y, which is substantially orthogonal to the first direction X.

With reference to the embodiment illustrated in the figures, the fixing means comprises a first fixing element 42 and a second fixing element 43 that have a spherical shape and are inserted respectively into a first opening 47 and into a second opening 48, made aligned and superimposed on the first direction X in the guiding means 41. The first fixing element 42 and the second fixing element 43 are maintained protruding from the pushing means such as to engage respectively a first coupling notch 62 and a second coupling notch 63 of the coupling element 60 in mounting configuration A.

Pushing means comprises actuating means, in particular a first actuator 44 and a second actuator 45, for example of pneumatic or mechanical type, connected respectively to the first fixing element 42 and to the second fixing element 43. By activating the actuators 44, 45, it is possible to move the fixing elements 42, 43 alternatively to a retracted position or to a protruding position, in which the fixing force is applied by the fixing elements 42, 43 to the coupling notches 62, 63. In an alternative embodiment that is not shown the actuators 44, 45 can be replaced by elastic means that is suitable for coupling with the fixing elements 42, 43.

The first opening 47 and the second opening 48 are provided with stopping portions that are not illustrated in the figures, to prevent the fixing elements 42, 43 completely exiting from the openings 47, 48, i.e. to enable the latter to protrude by a preset amount.

The coupling notches 62, 63 have a spherical cap shape with a curvature radius that is less than the curvature radius of the fixing elements 42, 43 such that the latter abut along respective substantially annular contact surfaces 65, 66.

The first opening 47 comprises a cylindrical hole having a diameter that is such as to house the first fixing element 42 with much reduced radial clearance 42.

When the first fixing element 42 abuts on the first coupling notch 62 and pushes the coupling element 60 against the rectilinear groove 49 along the second direction Y, the dosing unit 2 is locked in a firm and precise manner, prevented from moving in the first direction X, in the second direction Y and in a third direction Z that is orthogonal to the first direction X and to the second direction Y.

The second opening 48 comprises, on the other hand, a through slot that is elongated the first direction X to enable the second fixing element 43 to adapt to the position of the second coupling notch 63 and compensate for variations in distance between the latter and the first coupling notch 62 along the first direction X.

When the second fixing element 43 abuts on the second coupling notch 63 and pushes the coupling element 60 against the rectilinear groove 49, the dosing unit 2 is also locked rotationally around an axis that is parallel to the direction Y and passes through at the first fixing element 42.

The first coupling notch 62 and the second coupling notch 63 are made of corresponding inserts 67, 68 made of metal incorporated in the coupling element 60 to ensure greater stiffness and indeformability of the aforesaid coupling notches 62, 63 and greater precision and resistance in the abutment on the fixing elements 42, 43.

The dosing unit 2 also comprises stop means arranged for preventing or enabling the piston means 3 to run inside the cavity 4 of the casing means 5 along the first axis W1. In particular, the stop means locks the piston means 3 in relation to the casing means 5 in a preset linear and angular position, in such a manner as to maintain the dosing unit 2 in an assembled condition R that is necessary for conveying and mounting/dismantling the joint means 10.

The stop means comprises, in particular, a stop pin 70 that is slidingly assembled in a first housing 71, made on a side wall of the lower cylindrical portion 52 c of the covering element 52, and arranged for engaging a second housing 73, obtained on an external wall 6 a of the first end portion 6, at the opening of the seat 16.

The second housing 73 comprises a hole having dimensions that are substantially equivalent to those of the stop pin 70.

The stop pin 70 is movable parallel to the second direction Y, i.e. perpendicularly to the first longitudinal axis W1 and is moved by driving means of the supporting means 40 between a retracted position and an extended position. In the retracted position the stop pin 70 is completely contained in the first housing 71 in such a manner as not to interact with the first end portion 6 and enable the piston means 3 to move. In the extended position the stop pin 70 is inserted into the second housing 73 and prevents the piston means 3 from moving along and rotating around the first longitudinal axis W1 determining the assembled condition R of the dosing unit 2.

A drive pin 75, fixed transversely to the stop pin 70, is engaged by a drive stem 74 of the driving means. The drive stem 74 is parallel to the stop pin 70 and is driven by linear actuating means 76, comprising for example a pneumatic cylinder, of the driving means. The drive stem 74 has a radial groove that is suitable for receiving the drive pin 75.

In a mounting step of mounting the dosing unit 2 on the supporting means 40, the operator supports the dosing unit 2, arranged in the assembled condition R, by means of the gripping portion 52 a and inserts the coupling element 60 inside the guiding means 41 along the first direction X. The clearance between the coupling element 60 and the rectilinear groove 49 of the guiding means 41 permit easy and rapid insertion.

With the fixing elements 42, 43 maintained in the retracted position by the respective actuators 44, 45 inside the respective openings 47, 48, the coupling element 60 slides inside the guiding means 41 until it reaches a final position in which the aforesaid fixing elements 42, 43, pushed by the respective actuators 44, 45 to a protruding position abut on the respective coupling notches 62, 63, locking the dosing unit 2 in the mounting configuration A.

In this configuration, the drive pin 75 of the stop pin 70 is housed in the radial groove of the drive stem 74.

By performing the operation in reverse order, i.e. by removing the coupling element 60 from the guiding means 41, with the fixing elements 42, 43 maintained in the retracted position by the respective actuators 44, 45 it is possible to dismantle the dosing unit 2 from the supporting means 40.

Once the dosing unit 2 is inserted in the supporting means 40, the stop pin 70 still maintains the piston means 3 fixed to the casing means 5, locked in the assembled condition R in a set linear and angular position to enable the movement means 101 to move the joint means 10 along the second longitudinal axis W2 until the clutch portion 11 is inserted inside the seat 16 of the first end portion 6. Once the locking means 12 has been driven to fix mutually the clutch portion 11 to the seat 16, the stop pin 70 is disengaged from the piston means 3. In particular, the linear actuating means 76 is activated in such a manner as to move the stop pin 70 in the retracted position so as to enable the piston means 3 to move freely.

In one version of the apparatus that is not illustrated in the figures, the stop pin 70 engages a third housing made in the guiding means 41, to prevent the coupling element 60 from sliding, i.e. the dosing unit 2 from being extracted from the supporting means 40.

Owing to the dosing apparatus 1 of the invention it is thus possible to connect and lock the dosing unit to the respective supporting means 40 in a quickly, easy and simultaneously precise and firm manner.

It is important to note that the mounting procedure can be performed by only one operator and is made particularly easy by the shape and the dimensions of the guiding means 41 and of the coupling means 60 provided with clearance. The fixing elements driven by the respective actuators 44, 45 further enable the dosing unit 2 to be locked automatically when the latter has reached the desired position.

The entire mounting operation is made even easier by the stop means, and in particular by the stop pin 70 that in the assembled condition R, fixes the piston means 3 to the casing means 5. In this manner, the operator can support the dosing unit 2 by means of the gripping portion 52 a and insert the coupling element 60 inside the guiding means 41 along the first direction X without worrying about supporting also the piston means 3, as usually occurs in known dosing syringes.

It should be noted that also the disengagement of the stop means 70 from the piston means 3 to enable movement in the cavity 4 occurs automatically by means of the driving means, in particular the drive stem 74 and the linear actuating means, 76.

The procedure for dismantling the dosing unit 2 from the supporting means 40 is similarly easy and quickly and occurs by manually removing the coupling means 60 from the guiding means 41 along the first direction X. 

1-18. (canceled)
 19. A dosing apparatus comprising a dosing unit including a piston arrangement movable along a first axis in a cavity of a casing arrangement and a joint arrangement for removably connecting a first end portion of said piston arrangement to a movement arrangement arranged for moving said piston arrangement, wherein said first end portion comprises a seat adapted for receiving a clutch portion of said joint arrangement, said clutch portion being connectable in, and disconnectable from, said seat along a coupling direction substantially parallel to said first axis.
 20. Apparatus according to claim 19, wherein said joint arrangement comprises a locking arrangement for reversibly fixing said clutch portion to said seat in a coupling configuration.
 21. Apparatus according to claim 20, wherein said locking arrangement comprises at least one stop element associated with said clutch portion and movable in such a way as to engage or disengage a respective housing of said seat for respectively locking or releasing said first end portion on or from said joint arrangement.
 22. Apparatus according to claim 21, comprising an actuating arrangement acting on said stop element to at least maintain this latter engaged in the respective housing.
 23. Apparatus according to claim 19, wherein said joint arrangement comprises a connecting element, which includes said clutch portion, and a further connecting element having an end portion connected with said movement arrangement, said connecting element and said further connecting element being rotatably connected by a spherical element in such a way as to transmit a traction/compression force between said movement arrangement and said piston arrangement.
 24. Apparatus according to claim 23, wherein said further connecting element is connected with said movement arrangement so as to be movable linearly along, and in rotation about, a second axis.
 25. Apparatus according to claim 23, wherein said connecting element comprises a fork portion opposite to said clutch portion and said further connecting element comprises a further fork portion opposite the end portion connectable to the movement arrangement, said fork portion and said further fork portion comprising respective pairs of arms which contain said spherical element and are arranged on respective planes substantially orthogonal to one another.
 26. Apparatus according to claim 25, wherein said joint arrangement includes a sleeve containing at least said fork portions and connected to said connecting elements through pins so as to transmit a rotation torque between said movement arrangement and said piston arrangement.
 27. Apparatus according to claim 26, wherein said sleeve is connected to said connecting element and to said further connecting element, respectively, through a first pin and a second pin, said first pin and said second pin being substantially parallel to one another and transverse, in particular substantially orthogonal, to said first axis.
 28. Apparatus according to claim 27, wherein said first pin is fixed at respective opposite ends to said sleeve and is rotatably housed in a first through opening of said connecting element, said first through opening being such as to allow an axial displacement to said first pin along said coupling direction.
 29. Apparatus according to clann 19, wherein said joint arrangement comprises a connecting element equipped to an end of said clutch portion, the opposite end of said connecting element being connectable to said movement arrangement, in such a way as to be movable linearly along, and in rotation about, a second axis.
 30. Apparatus according to claim 29, wherein said joint arrangement comprises a locking arrangement for reversibly fixing said clutch portion to said seat in a coupling configuration and wherein said locking arrangement comprises an upper chamber defined by said clutch portion, by said seat and by a seal arrangement, which is interposed between said clutch portion and said seat, said upper chamber being connectable to a vacuum source, particularly a vacuum circuit, in such a way as to generate a connecting force able to block said clutch portion in said seat in said coupling configuration.
 31. Apparatus according to claim 30, wherein said joint arrangement comprises an abutting arrangement to define a reciprocal axial position between said first end portion and said clutch portion in said coupling configuration.
 32. Apparatus according to claim 31, wherein said abutting arrangement comprises a first abutting pin fixed to a bottom wall of said seat, a second abutting pin fixed to said clutch portion and an intermediate element with a spherical shape interposed between, and abutted by, said first abutting pin and said second abutting pin in said coupling configuration.
 33. Apparatus according to claim 30, wherein in said coupling configuration said seal arrangement are compressed between said clutch portion and an internal wall of said seat so as to transmit a rotation torque and/or a traction/compression force from said movement arrangement and said piston arrangement.
 34. Apparatus according to claim 29, wherein said clutch portion can be arranged inside said seat in said coupling configuration so that said first axis and second axis are misaligned and/or tilted to each other.
 35. Apparatus according to claim 19, and further comprising a transmission arrangement arranged for connecting said first end portion to said clutch portion in such a way as to define a reciprocal angular position and/or to cooperate to transmit a rotation torque between said movement arrangement and said piston arrangement.
 36. Apparatus according to claim 35, wherein said transmission arrangement comprises at least one dowel fixed to said clutch portion and arranged for engaging in a further seat obtained on said first end portion. 